A note scrawled in a child's handwriting arrived for American troops in Afghanistan around Christmastime. The missive — "Hope you make it" — is taped to the wall above the only trash can in the check-in and hand washing area, delivering comfort and humor to airmen, soldiers, sailors and Marines as they enter a communal dining facility.

That note has since disappeared. Its fate unknown.

But its four simple words have become a morale-boosting catchphrase, maybe even a rallying cry of sorts, at the base.

"Going on a mission? 'Hope you make it.' Going on leave? 'Hope you make it.' Going to the restroom? You guessed it: 'Hope you make it!,'" Maj. Sean Papworth writes in an article posted Tuesday on the 438th Air Expeditionary Wing's website.

And the identity of its author — known only by the signature "Gavin" — is a source of curiosity for the men and women rotating in with the NATO Air Training Command in Kabul.

Gavin's note is believed to have come from an elementary school in Shreveport, according to a U.S. Air Force spokesman. "The evidence is quite circumstantial; but in the way things work with care packages to the troops, it's somewhat solid," Senior Master Sgt. Mike Hammond says in an e-mail to The Times.

"When the card was displayed over the previous holiday season, ... one of the Gavin Fans remembers noticing that it was hanging in a group of cards that had been sent from an elementary school in Shreveport. He does not remember the name of the school, but that it was from Shreveport," Hammond writes.

Gavin's card was not individually marked. "But since we generally hang cards up right out of the box, it's more than likely Gavin's card came from there since his was in with other Shreveport cards," the spokesman continues. "It may be a needle in a haystack; but if enough folks read or see or hear the story, then we might just get lucky."

Young Gavin's four words — "Hope you make it" — show him to be "wise beyond his years," Papworth writes. "He wished me well — while being slightly realistic about the role I lived as a deployed member of our expeditionary military service."

"I may not make it, but he hopes I do. That is a profound comfort from a presumed grade schooler."

Service members have since immortalized Gavin's phrase "Hope you make it" on posters, coffee mugs and shoulder patches. There's even a Gavin Fan Club at Forward Operating Base Oqab in Kabul, Papworth writes.

"Even something as little as that card can make our day," says Hammond, the base spokesman. "And in this case, it has taken on a life of its own!"

Service members hope to meet Gavin one day and "share personally how his small note has impacted morale here," Hammond adds.

Papworth — who appeared in an online video last year sending holiday greetings to his wife, two sons and friends and family in Utah — hopes to someday let Gavin know "the great joy that his little phrase brought to our happy lot. I know that I and those working with me will not forget this saying. It became a significant part of our deployed life.

"And after successfully completing 365 days deployed, all I want to say in conclusion is ... THANK YOU, Gavin — 'I made it!' says Papworth, who will be redeployed after spending a year in Kabul.